Duplexer



FIG. 1 is a right-front perspective view of a duplexer showing the new design;

FIG. 2 is a top view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof; and,

FIG. 5 is a front view thereof.

The broken lines shown in FIGS. 1-5 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a duplexer, as shown and described. 